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SAN FRANCISCO — Google's vision for wearable technology took another ambitious leap forward Thursday when the world's largest Internet search company announced it is developing a smart contact lens.

The lens measures glucose in tears using a wireless chip and miniaturized glucose sensor. While at a very early stage, Google hopes the technology could help people manage diabetes better.

The project is the latest invention to emerge from the company's Google X unit, which works on long-term, risky new technology that may never become commercially successful but has the potential to change the way people live in drastic ways. The unit has already produced self-driving cars and connected eyewear called Google Glass.

Google said it went public with the contact lens project at an early stage because it is looking for expert partners who could bring the technology to market in the future.

Diabetes sufferers sometimes do not check their glucose levels as often as they should because those checks are usually disruptive or painful, such as pricking a finger to do a blood test. Researchers have been looking for less intrusive ways to check glucose, through sweat, saliva, urine or tears.

It's very difficult to measure glucose levels in the body with tears, partly because there's not much of the liquid available and it is hard to collect.

"We wondered if miniaturized electronics — think chips and sensors so small they look like bits of glitter, and an antenna thinner than a human hair — might be a way to crack the mystery of tear glucose and measure it with greater accuracy," Google said.

To make the contact lens, Google had to design its own tiny chips and mount them on very thin, flexible, plastic-like film. The chip and a sensor are embedded between two layers of soft contact lens material. A tiny pinhole in the lens lets tear fluid from the surface of the eye to seep into the glucose sensor. The prototypes can take a glucose level reading once every second, Google said.

The project's co-founders, Brian Otis and Babak Parviz, worked together at the University of Washington. Parviz joined Google X to work on Google Glass and Otis followed soon after and started trying to build a contact lens from scratch.

Google said it has done "multiple studies" to test the comfort and functionality of the lens and explore how tear glucose correlates with blood glucose, particularly in people with diabetes. It is also talking about the technology with the Food & Drug Administration.